Locked nucleic acid real-time polymerase chain reaction method identifying two polymorphisms of hepatitis B virus genotype C2 infections,rt269L and rt269I

BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive method capable of identifying both types in chronic hepatitis B(CHB)patients infected with genotype C2 should be developed.AIM To develop a novel simple and sensitive locked nucleic acid(LNA)-real timepolymerase chain reaction(RT-PCR)method capable of identifying two rt269 types in CHB genotype C2 patients.METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types.Using synthesized DNAs of the wild type and variant forms,melting temperature analysis,detection sensitivity,and endpoint genotyping for LNA-RT-PCR were performed.The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms,and these results were compared with those obtained by a direct sequencing protocol.RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes,two rt269L types[‘L1’(WT)and‘L2’]and one rt269I type(‘I’)in single(63 samples,72.4%)or mixed forms(24 samples,27.6%)in 87(92.6%sensitivity)of 94 samples from Korean CHB patients.When the results were compared with those obtained by the direct sequencing protocol,the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples(98.9%specificity).CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms,rt269L and rt269I,in CHB patients with genotype C2 infections.This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.

Global epidemiology of hepatitis C virus infection: an up-date of the distribution and circulation of hepatitis C virus genotypes

AIM To review Hepatitis C virus(HCV) prevalence and genotypes distribution worldwide.METHODS We conducted a systematic study which represents one of the most comprehensive effort to quantify global HCV epidemiology,using the best available published data between 2000 and 2015 from 138 countries(about 90% of the global population),grouped in 20 geographical areas(with the exclusion of Oceania),as defined by the Global Burden of Diseases project(GBD). Countries for which we were unable to obtain HCV genotype prevalence data were excluded from calculations of regional proportions,although their populations were included in the total population size of each region when generating regional genotype prevalence estimates.RESULTS Total global HCV prevalence is estimated at 2.5%(177.5 million of HCV infected adults),ranging from 2.9% in Africa and 1.3% in Americas,with a global viraemic rate of 67%(118.9 million of HCV RNA positive cases),varying from 64.4% in Asia to 74.8% in Australasia. HCV genotype 1 is the most prevalent worldwide(49.1%),followed by genotype 3(17.9%),4(16.8%) and 2(11.0%). Genotypes 5 and 6 are responsible for the remaining < 5%. While genotypes 1 and 3 are common worldwide,the largest proportion of genotypes 4 and 5 is in lower-income countries. Although HCV genotypes 1 and 3 infections are the most prevalent globally(67.0% if considered together),other genotypes are found more commonly in lowerincome countries where still account for a significant proportion of HCV cases.CONCLUSION A more precise knowledge of HCV genotype distribution will be helpful to best inform national healthcare models to improve access to new treatments.

Hepatitis C virus prevalence and genotype distribution inPakistan:Comprehensive review of recent data

Hepatitis C virus(HCV) is endemic in Pakistan and its burden is expected to increase in coming decades owing mainly to widespread use of unsafe medical procedures. The prevalence of HCV in Pakistan has previously been reviewed. However, the literature search conducted here revealed that at least 86 relevant studies have been produced since the publication of these systematic reviews. A revised updated analysis was therefore needed in order to integrate the fresh data. A systematic review of data published between 2010 and 2015 showed that HCV seroprevalence among the general adult Pakistani population is 6.8%, while active HCV infection was found in approximately 6% of the population. Studies included in this review have also shown extremely high HCV prevalence in rural and underdeveloped peri-urban areas(up to 25%), highlighting the need for an increased focus on this previously neglected socioeconomic stratum of the population. While a 2.45% seroprevalence among blood donors demands immediate measures to curtail the risk of transfusion transmitted HCV, a very high prevalence in patients attending hospitals with various non-liver disease related complaints(up to 30%) suggests a rise in the incidence of nosocomial HCV spread. HCV genotype 3a continues to be the most prevalent subtype infecting people in Pakistan(61.3%). However, recent years have witnessed an increase in the frequency of subtype 2a in certain geographical sub-regions within Pakistan. In Khyber Pakhtunkhwa and Sindh provinces, 2a was the second most prevalent genotype(17.3% and 11.3% respectively). While the changing frequency distribution of various genotypes demands an increased emphasis on research for novel therapeutic regimens, evidence of high nosocomial transmission calls for immediate measures aimed at ensuring safe medical practices.

Hepatitis C virus genotype 6:Virology,epidemiology,genetic variation and clinical implication

Hepatitis C virus(HCV)is a serious public health problem affecting 170 million carriers worldwide.It is a leading cause of chronic hepatitis,cirrhosis,and liver cancer and is the primary cause for liver transplantation worldwide.HCV genotype 6(HCV-6)is restricted to South China,South-East Asia,and it is also occasionally found in migrant patients from endemic countries.HCV-6 has considerable genetic diversity with23 subtypes(a to w).Although direct sequencing followed by phylogenetic analysis is the gold standard for HCV-6 genotyping and subtyping,there are also now rapid genotyping tests available such as the reverse hybridization line probe assay(INNO-LiPAⅡ;Innogenetics,Zwijnaarde,Belgium).HCV-6 patients present with similar clinical manifestations as patients infected with other genotypes.Based on current evidence,the optimal treatment duration of HCV-6 with pegylated interferon/ribavirin should be 48 wk,although a shortened treatment duration of 24 wk could be sufficient in patients with low pretreatment viral load who achieve rapid virological response.In addition,the development of direct-acting antiviral agents is ongoing,and they give high response rate when combined with standard therapy.Herein,we review the epidemiology,classification,diagnosis and treatment as it pertain to HCV-6.

Distribution and changes in hepatitis C virus genotype in China from 2010 to 2020

BACKGROUND Hepatitis C virus(HCV)causes a large number of infections worldwide.New infections seem to be increasing according to a report of the World Health Organization in 2015.Although direct-acting antivirals are quite effective for most genotypes of the HCV,some genotypes fail to respond.Therefore,the trend of genotype distribution is vital to better control the development of this infection.AIM To analyze the distribution and trends of the HCV genotype before and after the emergence of direct-acting antivirals in China.METHODS We searched all literature published in five electronic databases-China National Knowledge Infrastructure,Wan Fang Data,VIP Chinese Journal Database,Chinese Biomedical Literature Service System,and PubMed-from January 1,2010 to December 31,2020.The search strategy combined medical subject headings and free-text terms,including“hepatitis C virus”or“HCV”and“genotype”or“subtype”and“China”or“Chinese”.Additional relevant articles were searched by manual selection.Data were extracted to build a database.All of the data were totaled according to regions,periods,routes of transmission,and sexes.The percentages in various stratifications were calculated.RESULTS There were 76110 samples from 30 provinces included in the study.Genotype 1(G1)accounted for 58.2%of cases nationwide,followed by G2,G6,G3b,G3a,unclassified and mixed infections(17.5%,7.8%,6.4%,4.9%,1.8%,and 1.2%,respectively).The constitution of genotype varied among different regions,with G6 and G3b being more common in the south and southwest,respectively(28.1%,15.4%).The past ten years have witnessed a decrease in G1 and G2 and an increase in G3 and G6 in almost all regions.The drug-use population had the most abundant genotypes,with G6 ranking first(33.3%),followed by G1 and G3b(23.4%,18.5%).CONCLUSION G3 and G6 pose a new challenge for HCV infection.This study revealed the distribution of HCV genotypes in China over the past 10 years,providing information for HCV management strategies.

Current status and emerging challenges in the treatment of hepatitis C virus genotypes 4 to 6

Hepatitis C virus(HCV) genotypes 4, 5 and 6 are mainly present in Africa, the Middle East and Asia and they have been less extensively studied with respect to epidemiology, natural disease history and therapeutic endpoints. Response rates to a 48-wk combined peginterferon/ribavirin treatment range to 40%-69% for HCV 4, 55%-60% for HCV 5 and 60%-90% for HCV 6. Response-guided schedules are recommended to optimize the outcomes of peginterferon/ribavirin treatment in HCV 4 and, in form of preliminarydata, for HCV 6, but no data are yet available to support such an individualization of therapy for HCV 5. Recently, the direct-acting antivirals(DAAs) with pan-genotypic activities simeprevir, sofosbuvir and daclatasvir have been recommended in triple regimens with peginterferon/ribavirin for the treatment of HCV genotypes 4 to 6 infections. In the future, DAA-based interferon-free therapies are awaited to drastically improve treatment outcomes in HCV. However, efforts to improve treatment outcomes with peginterferon/ribavirin should continue, as the HCV 4-6 infected population is mainly based in resource-limited settings with restricted access to the costly DAAs.

Hepatitis C virus in Pakistan:A systematic review of prevalence,genotypes and risk factors

In Pakistan more than 10 million people are living with Hepatitis C virus (HCV), with high morbidity and mortality. This article reviews the prevalence, genotypes and factors associated with HCV infection in the Pakistani population. A literature search was performed by using the keywords; HCV prevalence, genotypes and risk factors in a Pakistani population, in Pubmed, PakMediNet and Google scholar. Ninetyone different studies dating from 1994 to May 2009 were included in this study, and weighted mean and standard error of each population group was calculated. Percentage prevalence of HCV was 4.95% ± 0.53% in the general adult population, 1.72% ± 0.24% in the pediatric population and 3.64% ± 0.31% in a young population applying for recruitment, whereas a very high 57% ± 17.7% prevalence was observed in injecting drug users and 48.67% ± 1.75% in a multi-transfused population. Most prevalent genotype of HCV was 3a. HCV prevalence was moderate in the general population but very high in injecting drug users and multi-transfused populations. This data suggests that the major contributing factors towards increased HCV prevalence include unchecked blood transfusions and reuse of injection syringes. Awareness programs are required to decrease the future burden of HCV in the Pakistani population.

Interleukin 28B polymorphisms as predictor of response in hepatitis C virus genotype 2 and 3 infected patients

Single nucleotide polymorphisms near the interleukin28B(IL-28B)gene have been identified as strong predictors of both spontaneous or Peg-interferon(Peg-IFN)and ribavirin(RBV)induced clearance of hepatitis C virus(HCV).Several studies have shown that,in patients with genotype 1(GT-1),rs12979860 C/C and rs8099917T/T substitutions are associated with a more than twofold increase in sustained virological response rate to Peg-IFN and RBV treatment.Although new treatment regimens based on combination of DAA with or without IFN are in the approval phase,until combination regimens with a backbone of Peg-IFN will be used,we can expect that IL28B holds its importance.The clinical relevance of IL28B genotyping in treatment of patients infected with HCV genotype 2(GT-2)and 3(GT-3)remains controversial.Therefore,after a careful examination of the available literature,we analyzed the impact of IL28B in GT-2 and-3.Simple size of the studies and GT-2 and GT-3 proportion were discussed.An algorithm for the practical use of IL28B in these patients was suggested at the aim of optimizing treatment.

Injecting drug use: A vector for the introduction of new hepatitis C virus genotypes

Hepatitis C virus(HCV) genotypes' monitoring allows real-time insight into the dynamic changes that occur in the global epidemiological picture of HCV infection. Intravenous drug use is currently the primary driver for HCV transmission in developed and developing countries. The distribution of HCV genotypes/subtypes differs significantly between people who inject drugs(PWID) and the general population. HCV genotypes that previously exhibited a limited geographical distribution(3a,4) are becoming more prevalent in this high-risk group. Immigration from HCV-endemic countries and the evolving networks of HCV transmission in PWID influence HCV genotypes distribution in Europe. Social vulnerabilities(e.g.,unemployment,homelessness,and limited access to social and healthcare insurances systems) are important triggers for illicit drug use,which increases the associated risks of HCV infection and the frequent emergence of less prevalent genotypes. Genotype/subtype determination bears important clinical consequences in the progression of liver disease,susceptibility to antiviral therapies and the emergence of resistance-associated variants. An estimated half of the chronically HCV-infected PWID are unaware of their infection,and only one in ten of those diagnosed enter treatment. Nevertheless,PWID exhibit high response rates to new antiviral regimens,and the level of HCV reinfection is unexpectedly low. The focus of the healthcare system must be on the early detection and treatment of infection,to avoid late presentations that are associated with high levels of viremia and liver fibrosis,which may diminish the therapeutic success rate.

Impact of virus genotype on interferon treatment of patients with chronic hepatitis C: a multicenter controlled study

BACKGROUND: Some factors have been reported to besassociated with a greater likelihood of sustained viral re-sponse ( SVR) in the interferon (IFN) treatment of chronichepatitis C. The factors include HCV genotype, HCVRNA level in serum, state of liver disease, baseline bodyweight, age, sex, and race. The aim of this trial was to in-vestigate the influence of HCV genotype on the IFN treat-ment of patients with chronic hepatitis C.METHODS: The genotypes of HCV virus were determinedin the patients with chronic hepatitis C from several hospi-tals of China enrolled into the randomized, opened andcontrolled trial of Peg-IFN alpha-2a (pegasys) treatment,controlled with IFN-α-2a (roferon-A). The serum ALTlevels and HCV RNA concentrations of the patients weredetected before and at the end of treatment and during thefollow-up. The influence of HCV genotype on the IFNtreatment of patients with chronic hepatitis C was analyzedin intention-to-treat (ITT) population.RESULTS: The HCV genotypes of 202 patients were deter-mined. Of these patients, 158(78.22%) were infected withgenotype 1 HCV and 44(21.78%) with genotype non-1.The viral response at the end of treatment (ETVR) andsustained viral response (SVR) rates were 53.80% and25.32% respectively in patients with genotype 1 HCV, butthey were 61.36% and 43.18% in patients with genotypenon-1. The difference of SVR between patients with geno-type 1 HCV and those with genotype non-1 was significant(P =0.021). After being grouped by the used drugs, theETVR rates of patients infected with genotype 1 and non-1HCV were 76.83% and 80.95% in the patients treated withpegasys (P =0.686); but their SVR rates were 35.37% and66.67% (P =0. 01). The viral relapse rate of genotype 1HCV (55.56%) was significantly higher than that of geno-type non-1 HCV (23.53%) (P=0.02). In roferon-A group,the ETVR and SVR rates of patients with genotype 1 HCVwere 28.95% and 14.47% respectively, which were lowerbut not more significant than those of patients with geno-type non-1 HCV (43.48% and 21.74%). Moreover, the vi-ral relapse rate of genotype 1 HCV (72.73%) was higherbut not more significant than that of genotype non-1 HCV(50.00%) (P=0.21).CONCLUSION: HCV genotype could affect the efficacies,mainly sustained responses, of IFN treatment in patientswith chronic hepatitis C, and the effects of IFN are relatedto drugs and therapeutic course.

Hepatitis C virus genotypes in Serbia and Montenegro: The prevalence and clinical signifi cance

AIM: To investigate the prevalence of hepatitis C virus (HCV) genotypes in Serbia and Montenegro and their in? uence on some clinical characteristics in patients with chronic HCV infection.METHODS: A total of 164 patients was investigated. Complete history, route of infection, assessment of al-cohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene se-quencing of 5’ NTR type-specifi c PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows (version 10.0) was used for univariate regression analysis with further multivariate analysis. RESULTS: The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 (mainly the subtype 1b) was found to be independent of age in sub-jects older than 40 years, high viral load, more severe necro-in? ammatory activity, advanced stage of fi brosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive pre-dictive factors for the genotypes 1b and 3a, respectively. CONCLUSION: In Serbia and Montenegro, the geno-types 1b and 3a predominate in patients with chronic HCV infection. The subtype 1b is characteristic of older patients, while the genotype 3a is common in drug abus-ers. Association of the subtype 1b with advanced liverdisease, higher viral load and histological activity sug-gests earlier infection with this genotype and eventually its increased pathogenicity.

Hepatocellular carcinoma or interferon-based therapy history attenuates sofosbuvir/ribavirin for Japanese genotype 2 hepatitis C virus

AIM To investigate the real-world efficacy and safety of sofosbuvir/ribavirin(SOF/RBV) therapy for Japanese patients with genotype 2 hepatitis C virus(GT2-HCV).METHODS A total of 182 patients with GT2-HCV infection who received SOF/RBV therapy for 12 wk at our hospital were enrolled. The patients comprised 122 men and 60 women(age range: 17-84 years; mean age ± SD: 60.1 ± 12.1 years). Relationships between virological response and clinical data were examined by logistic regression analyses. RESULTS The proportions of patients with liver cirrhosis and history of hepatocellular carcinoma(HCC) were 29.0% and 17.3%, respectively. The proportion of patients with prior interferon(IFN)-based therapy was 25.6%. SOF/RBV therapy rapidly decreased HCV RNA levels. Several patients required RBV dose reduction because of anemia or fatigue. Four patients discontinued the therapy. The rates of sustained virological response at 12 wk after the end of treatment were 87.9%(intention to treat: 160/182) and 94.1%(per protocol: 159/169). Multivariate analyses showed that history of HCC or IFN-based therapy independently reduced the efficacy of SOF/RBV therapy. CONCLUSION SOF/RBV therapy for GT2-HCV is safe, highly tolerated, and effective. History of HCC or IFN-based therapy independently reduces the efficacy of this treatment.

Determining hepatitis C virus genotype distribution among high-risk groups in Iran using real-time PCR

AIM:To assess hepatitis C virus(HCV)genotype patterns among high-risk Iranian groups,using real-time RT-PCR.METHODS:In this study,we evaluated the distribution of different HCV genotypes among injection drug users and other high-risk groups over a 4-year period(from 2009 to 2012)using real-time polymerase chain reaction(PCR).Sera from 888 HCV-infected patients residing in southern and southwest Iran were genotyped using real-time PCR with common primers and specific probes.These patients were grouped into distinct exposure categories.Illicit drug users constituted the primary group and were further evaluated for HCV genotype distribution and parameters such as age range.RESULTS:Of the examined HCV-infected patients,62%were substance abusers,although the route of transmission could not be determined in approximately 30%of these patients.HCV genotyping revealed that Gt1 was the most prevalent genotype among the drug users as well as among patients with thalassemia,hemophilia,solid organ recipients and those on hemodialysis.Mixed infections were only seen in addict groups,where Gt2 genotype was also found.The highest frequencies in HCV-positive addict patients were observed in the 31-40 age group.Our research also showed that the addiction age has increased,whereas the addiction rate has dropped in this region.Most illicit drug users had more than one risk factor such as tattoo and/or a history of imprisonment.CONCLUSION:This study revealed that the most common HCV-infection route and HCV-genotype in southern and southwest Iran was illicit drug abuse and Gt1,respectively.

Differences in viral kinetics between genotypes 1 and 3 of hepatitis C virus and between cirrhotic and non-cirrhotic patients during antiviral therapy

AIM: To evaluate the impact of hepatitis C virus (HCV) infection with genotype 1 or 3 and the presence or absence of liver cirrhosis (LC) in the early viral kinetics response to treatment. METHODS: Naive patients (n = 46) treated with interferon-α (IFN-α) and ribavirin and followed up with frequent early HCV-RNA determinations were analysed. Patients were infected with genotype 1 (n = 28, 7 with LC) or 3 (n = 18, 5 with LC). RESULTS: The fi rst phase decline was larger in geno- type 3 patients than in genotype 1 patients (1.72 vs 0.95 log IU/mL, P < 0.001). The second phase slope decline was also larger in genotype 3 patients than in genotype 1 patients (0.87 vs 0.15 log/wk, P < 0.001). Differences were found in both cirrhotic and non-cirrhotic patients. Genotype 1 cirrhotic patients had a slower 2nd phase slope than non-cirrhotic patients (0.06 vs 0.18 log/wk, P < 0.02). None of genotype 1 cirrhotic patients had a 1st phase decline larger than 1 log (non-cirrhotic patients: 55%, P < 0.02). A similar trend toward a slower 2nd phase slope was observed in genotype 3 cirrhotic pa- tients but the 1st phase slope decline was not different. Sustained viral response was higher in genotype 3 pa- tients than in genotype 1 patients (72% vs 14%, P < 0.001) and in genotype 1 non-cirrhotic patients than in genotype 1 cirrhotic patients (19% vs 0%). A secondphase decline slower than 0.3 log/wk was predictive of non-response in all groups. CONCLUSION: Genotype 3 has faster early viral decline than genotype 1. Cirrhosis correlates with a slower 2nd phase decline and possibly with a lower 1st phase slope decline in genotype 1 patients.

Treatment of hepatitis C virus genotype 4 with peginterferon alfa-2a: Impact of bilharziasis and fibrosis stage

AIM: To evaluate pegylated interferon alpha2a (PegIFN- α2a) in Egyptian patients with HCV genotype 4, and the impact of pretreatment viral load, co-existent bilharziasis and histological liver changes on response rate. METHODS: A total of 73 na?ve patients (61 with history of bilharziasis) with compensated chronic HCV genotype 4 were enrolled into: group A (38 patients) who received 180 mg PegIFN-alpha2a subcutaneously once weekly for a year and group B (35 patients) received IFN alpha-2a 3 MU 3 times weekly. Ribavirin was added to each regimen at a dose of 1200 mg. Patients were followed for 72 wk and sustained response was assessed. RESULTS: Significant improvement in both end of treatment response (ETR) (P < 0.002) and sustained response (SR) (P < 0.05) was noted with pegylated interferon, where ETR was achieved in 29 (76.3%) and 14 patients (40%) in both groups respectively, and 25 patients in group A (65.8%) and 9 (25.7%) in group B could retain negative viraemia by the end of follow up period. Sustained virological response (SVR) showed a significant negative correlation with age and positive correlation with pretreatment inflammation in patients receiving PegIFN. Viral clearance after 3 mo of therapy was associated with high incidence of ETR and SR (P < 0.001), but without significant difference between both forms of interferon. Significant improvement in response was achieved in patients with high grade fibrosis (grade 3 and 4) with PegIFN-α2a, where SR was seen in 5 out of 13 patients in group A, but none in group B. There was no significant difference in response betweenbilharzial and non-bilharzial patients in both groups. In terms of safety and tolerability, neutropenia was the predominant side effect; both drugs were comparable. CONCLUSION: PegIFN-α2a combined with ribavirin results in improvement in sustained response in HCV genotype 4, irrespective of history of bilharzial infestation.

Hepatitis C virus genotypes distribution and transmission risk factors in Luxembourg from 1991 to 2006

AIM:To analyze the Hepatitis C virus (HCV) genotype distribution and transmission risk factors in a population of unselected patients in Luxembourg. METHODS:Epidemiological information (gender, age and transmission risks) were collected from 802 patients newly diagnosed for hepatitis C and living in Luxembourg, among whom 228 patients referred from prison. Genotyping using 5'noncoding (5'NC) sequencing was performed. We compared categorical data using the Fisher's exact F-test and odds ratios (OR) were calculated for evaluating association of HCV genotype and risk factors. RESULTS:The sex ratio was predominantly male (2.2) and individuals aged less than 40 years represented 49.6% of the population. Genotype 1 was predominant (53.4%) followed by genotype 3 (33%). Among risk factors, intravenous drug usage (IVDU) was the most frequently reported (71.4%) followed by medical-related transmission (17.6%) including haemophilia, transfusion recipients and other nosocomial reasons. Genotype 3 was significantly associated to IVDU (OR = 4.84, P < 0.0001) whereas genotype 1 was significantly associated with a medical procedure (OR = 2.42, P < 0.001). The HCV genotype distribution from inmate patients differed significantly from the rest of the population (Chi-square test with four degrees of freedom, P < 0.0001) with a higher frequency of genotype 3 (46.5% vs 27.5%) and a lower frequency of genotype 1 and 4 (44.7% vs 56.8% and 5.3% vs 9.6%, respectively). IVDU was nearly exclusively reported as a risk factor in prison. CONCLUSION:We report the first description of the HCV genotype distribution in Luxembourg. The repartition is similar to other European countries, with one of the highest European prevalence rates of genotype 3 (33%). Since serology screening became available in 1991, IVDU remains the most common way of HCV transmission in Luxembourg.

Interleukin-28 and hepatitis C virus genotype-4:Treatment-induced clearance and liver fibrosis

AIM:To investigate the association between interleukin-28B(IL28B) genotype and response to treatment and hepatic fibrosis in patients with hepatitis C virus(HCV) genotype 4.METHODS:Two hundred and one HCV-genotype 4 patients were included.All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk.End of treatment response(ETR) was defined as loss of detectable serum HCV RNA at the end of treatment.Sustained viral response(SVR) was defined as loss of detectable serum HCV RNA at the end of 24 wk follow up.Genotyping of IL28B rs12979860 was performed using the TaqMan assay.We used logistic regression to estimate the adjusted odds ratio(aOR) and 95%CI.RESULTS:The study included 201 HCV-genotype 4 patients.The majority of patients were men(89.6%),with a median age of 47 years,inter-quartile range(40-51).Approximately 62.5% of patients had ETR,and 49.6% had SVR.Individuals who achieved SVR were more likely to be younger(χ 2 = 4.91,P = 0.027),and less likely to have fibrosis(χ 2 = 15.54,P < 0.0001),or inflammation(χ 2 = 7.58,P = 0.006).The genotype distribution of rs12979860 was 36.2%,49.0% and 14.8% for genotypes CC,CT,and TT,respectively.In these participants,rs12979860 genotype distribution did not differ by gender(P = 0.466),pretreatment viral load(P = 0.600),inflammation(P = 0.435),or fibrosis(P = 0.291).The frequencies of IL28B rs12979860 genotypes were TT(14.8%),CT(49.0%),and CC(36.2%).Compared to rs12979860 genotype TT,aORs(95%CI) for ETR and SVR were:CC genotype,[17.55(5.34-57.69) and 5.92(2.09-16.76),respectively];CT genotype,[5.15(1.80-14.78) and 2.48(0.94-6.52),respectively].In the current study,the patients who did not achieve ETR or SVR had a lower prevalence of rs12979860 CC(17.4% and 23.3%,respectively) than individuals who had ETR or SVR(47.9% and 47.2%,respectively).Individuals with rs12979860 CC genotype had approximately 6 times the odds of SVR compared to individuals with TT genotype(aOR = 5.92;95%CI:2.09-16.76).Similarly,patients with CT genotype had SVR more often than patients with TT genotype(aOR = 2.48;95%CI:0.94-6.52).Carrying at least one copy of the C allele(genotypes CT and CC) had almost 8 times the probability of ETR compared to those with genotype rs12979860 TT(aOR = 7.87;95%CI:2.84-21.82),and approximately 3 times the odds of SVR compared to those with genotype rs12979860 TT(aOR = 3.46;95%CI:1.37-8.74).In addition,data were consistent with a significant gene-dose relationship(aOR = 4.05/allele;95%CI:2.27-7.22).The association between rs12979860 genotype and SVR was similar among those who achieved and those who did not achieve SVR.CONCLUSION:In HCV-genotype 4 patients,rs12979860 is a sensitive predictor of viral clearance,independent of viral load,age,gender or fibrosis,with no similar relation to severity of fibrosis.

Screening and identification of bioactive compounds from citrus against non-structural protein 3 protease of hepatitis C virus genotype 3a by fluorescence resonance energy transfer assay and mass spectrometry

BACKGROUND Hepatitis C virus genotype 3a(HCV G3a)is highly prevalent in Pakistan.Due to the elevated cost of available Food and Drug Administration-approved drugs against HCV,medicinal natural products of potent antiviral activity should be screened for the cost-effective treatment of the disease.Furthermore,from natural products,active compounds against vital HCV proteins like non-structural protein 3(NS3)protease could be identified to prevent viral proliferation in the host.AIM To develop cost-effective HCV genotype 3a NS3 protease inhibitors from citrus fruit extracts.METHODS Full-length NS3 without co-factor non-structural protein 4A(NS4A)and codon optimized NS3 protease in fusion with NS4A were expressed in Escherichia coli.The expressed protein was purified by metal ion affinity chromatography and gel filtration.Citrus fruit extracts were screened using fluorescence resonance energy transfer(FRET)assay against the protease and polyphenols were identified as potential inhibitors using electrospray ionization-mass spectrometry(MS)/MS technique.Among different polyphenols,highly potent compounds were screened using molecular modeling approaches and consequently the most active compound was further evaluated against HCV NS4A-NS3 protease domain using FRET assay.RESULTS NS4A fused with NS3 protease domain gene was overexpressed and the purified protein yield was high in comparison to the lower yield of the full-length NS3 protein.Furthermore,in enzyme kinetic studies,NS4A fused with NS3 protease proved to be functionally active compared to full-length NS3.So it was concluded that co-factor NS4A fusion is essential for the purification of functionally active protease.FRET assay was developed and validated by the half maximal inhibitory concentration(IC50)values of commercially available inhibitors.Screening of citrus fruit extracts against the native purified fused NS4A-NS3 protease domain showed that the grapefruit mesocarp extract exhibits the highest percentage inhibition 91%of protease activity.Among the compounds identified by LCMS analysis,hesperidin showed strong binding affinity with the protease catalytic triad having S-score value of-10.98.CONCLUSION Fused NS4A-NS3 protease is functionally more active,which is effectively inhibited by hesperidin from the grapefruit mesocarp extract with an IC50 value of 23.32μmol/L.

Cladogynos orientalis Zipp. extracts inhibit cell culture-derived hepatitis C virus genotype 2a replication in Huh-7 cells through NS5B inhibition

Objective: To evaluate the potential anti-hepatitis C virus (HCV) activities of Cladogynos orientalis Zipp. ex Span and to investigate the molecular mode of action. Methods: Ethanolic and water extracts from various parts of Cladogynos orientalis were examined for cytotoxicity by MTT assay. Sub-cytotoxic concentrations of the extracts were used for further determining anti-HCV activity using cell culture-derived HCV genotype 2a propagated in HepaRG cell line. Immunofluorescence assay was performed to observe the effect on viruses at the pre-entry step. Mode of action at the post-entry step was investigated for the viral RNA and protein expressions by real time RT-PCR and Western blotting assays, respectively. Results: Although Cladogynos orientalis water extracts exhibited lower cytotoxicity than ethanolic extracts, all ethanolic extracts from roots, stems, and leaves of Cladogynos orientalis exhibited higher anti-HCV activities than water extracts. The highest anti-HCV activity was observed in infected cells treated with the extracts 5 h after absorption. No extracts showed pre-viral entry effect. At the post-viral entry step, only leaf ethanolic extracts inhibited NS5B expression, while all extracts did not inhibit HCV NS3 expression. Conclusions: Cladogynos orientalis ethanolic extracts could be further studied and the major active compound needs to be identified as a promising source for anti-HCV agents.

Hepatitis C virus genotypes in Myanmar

Myanmar is adjacent to India, Bangladesh, Thailand, Laos and China. In Myanmar, the prevalence of hepatitis C virus(HCV) infection is 2%, and HCV infection accounts for 25% of hepatocellular carcinoma. In this study, we reviewed the prevalence of HCV genotypes in Myanmar. HCV genotypes 1, 3 and 6 were observed in volunteer blood donors in and around the Myanmar city of Yangon. Although there are several reports of HCV genotype 6 and its variants in Myanmar, the distribution of the HCV genotypes has not been well documented in areas other than Yangon. Previous studies showed that treatment with peginterferon and a weight-based dose of ribavirin for 24 or 48 wk could lead to an 80%-100% sustained virological response(SVR) rates in Myanmar. Current interferon-free treatments could lead to higher SVR rates(90%-95%) in patients infected with almost all HCV genotypes other than HCV genotype 3. In an era of heavy reliance on direct-acting antivirals against HCV, there is an increasing need to measure HCV genotypes, and this need will also increase specifically in Myanmar. Current available information of HCV genotypes were mostly from Yangon and other countries than Myanmar. The prevalence of HCV genotypes in Myanmar should be determined.